Ultimate Amiga

Other => Amiga Hardware => Topic started by: MadAngus on September 21, 2012, 12:40:37 AM

Title: A1200 Schematics Rework
Post by: MadAngus on September 21, 2012, 12:40:37 AM
A1200 Hackers Resource Kit.

Been wanting to do this for a while and since I can't currently afford to learn electronics buy buying small kits to practice on, I thought I'd start with getting experience with schematics.
Note: Wherever this project ends up it will always just be a 'done for fun' Novice/Amateur project.

[Updated 22/10/12]
- Change of direction. Project summary rewritten.

The current crop of available A1200 hardware documents are predominately image scans and in many cases difficult to read. In that respect the goals of the A1200 Schematics Rework project is to produce new schematic drawings in readable formats.

This project aims to produce new schematics using actual schematic component drawings for Rev1-1D and Rev2 mainboards, with a view to producing a full mainboard schematic and PCB for the Rev2 mainboard.

In addition, as the project progresses custom chip specification documents will be reworked into a readable format as well as collating all the necessary component datasheets.

The final stage will be to collate additional relevant hardware information from all available sources and knowledge into a single document/schematic resource kit.

[Primary project goals]



Work-In-Progress releases will be attached below.
The current attachment is no longer valid as block type component drawings will not be used in the new schematics.

RedskullDC at EAB for the A1200 High res scans.
Title: Re: A1200 Schematics Rework
Post by: MadAngus on September 21, 2012, 12:40:53 AM
I've got the ball rolling on this and have attached the first wip pages of the schematics in the first post.

If you spot any errors or have any tips feel free to post and let me know.

Couple of questions and points:
At the right of the schematic you will notice a 16R4 chip, is this a Programmable Array Logic Chip or something altogether different?
[Edit] Answer - Yes its a PAL (Datasheet?)

[EDIT 21/09/12] The other question I forgot to ask is how many PCB layers does the A1200 board have?
[Edit 22/10/12] Answer - Cut a board in half and inspect the traces. :o

On the MC68881 chip I have forgotten to add the VCC label to _Size (pin 18).

You will notice some gate component graphics are not displayed properly. this is either due to Kicad not properly defining the curved lines as ellipses when plotting to svg. When opened in Inkscape it just draws them as polylines. Either that or it's Inkscape's implementation of svg that's causing some problem.
[Edit 22/10/12] Answer - Kicad problem it just draws them as polylines, confirmed.

I'll need to figure out what I'm going to do as a result of the svg problem. I wouldn't need svg if Kicad allowed the schematic to be scaled. I might ditch Kicad and try out Designspark, we'll see.
[Edit 22/10/12] Sticking to Kicad for it's open file format. I'll need access to this for documentation purposes.

[Edits 22/10/12 by MadAngus] Answering my own questions, PAL question answered by Bryce on AmiBay, Cheers.
Title: Re: A1200 Schematics Rework
Post by: MadAngus on November 24, 2012, 01:40:10 PM
Small update on this project.

Got most of the rev2 component datasheets and can now begin to create the schematic symbols.

I'll provide a list of the components I'm not sure about at a later date.
Title: Re: A1200 Schematics Rework
Post by: Ratteler on October 08, 2021, 07:46:37 AM
Just a bunp to see if anyone had finished an A1200 KiCad layout already.
Title: Re: A1200 Schematics Rework
Post by: FOL on November 16, 2021, 05:01:14 PM
Just a bunp to see if anyone had finished an A1200 KiCad layout already.

MadAngus, is MIA.
I have reached out a few times, I hope nothing has happened to him.
As its been around 7 years since his last activity.